Warfarin for Left Ventricular Thrombus in Nonischemic Cardiomyopathy With Acute Kidney Injury: A Case Report and Literature Review of Anticoagulation Strategies in Renal Impairment.

Left ventricular (LV) thrombus is a serious complication of cardiomyopathy with severely reduced ejection fraction, carrying significant risk of systemic embolization. While direct oral anticoagulants (DOACs) have emerged as a reasonable alternative to warfarin for LV thrombus treatment in the general population, no guideline-directed evidence exists for their use in patients with concomitant acute kidney injury (AKI) or significant renal impairment in this specific clinical context. We present the case of a 47-year-old male with newly diagnosed nonischemic cardiomyopathy (ejection fraction 25%), LV apical thrombus, and Kidney Disease: Improving Global Outcomes (KDIGO)-defined AKI attributed to type 1 cardiorenal syndrome, who was managed with heparin bridging to warfarin due to the absence of evidence supporting DOAC use for LV thrombus in the setting of renal dysfunction. The requirement for heparin-to-warfarin bridging prolonged the patient's hospitalization by five days, illustrating the tangible clinical and resource burden imposed by the current guideline gap. Chronic kidney disease (CKD) is present in approximately 45% of patients with heart failure with reduced ejection fraction; roughly two-thirds of heart failure hospitalizations are associated with a discharge estimated glomerular filtration rate below 60 mL/min/1.73 m², and AKI complicates approximately one-third of heart failure admissions, so this clinical scenario is far from rare. We additionally provide a literature review of the current evidence comparing DOACs and vitamin K antagonists (VKAs) for LV thrombus, DOAC pharmacokinetics in renal impairment, and the guideline landscape at this clinical intersection. Notably, every randomized trial comparing DOACs with warfarin for LV thrombus to date has explicitly excluded patients with moderate-to-severe renal impairment. This case and review underscore the need for prospective studies evaluating DOAC safety and efficacy for LV thrombus in patients with impaired renal function, which could reduce unnecessary hospital days and healthcare costs while maintaining safe anticoagulation.